>>793631I don't have the phylogeny of the family in my head
Wikipedia only says all 3 are in different tribes of the same subfamily (Cucurbitoideae)
From this pic it appears that pumpkins and cucumbers (in the bottom 2 tribes respictively) are closer to each other than any is to the bryony (which is in a bit more basal clade), so from the POV of the bryony they both are equidistant